Guy chars slices of sweet potato and onion before layering them with Gruyere cheese and a horseradish cream sauce in a baked gratin! Sign up for #discoveryplus to stream more of #GuysBigBite:. Get the dish ▶ Sign Up For Food Network ▶ We know something is certain– Guy Fieri's food is as fun, brave and fundamental as his epic personality. We hope you're starving, because this Man's creativity knows no limits. Open wide for Man's Big Bite!…